Tunnel kiln



G'. W. BOUTH.

TUNNEL KILN.

APPLlcATloN msu SEPT. a. 1920.

4 SHEETS-SHEET Patented Jan. 17, 1922.

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TUNNEL KILN.

G. W. BOOTH.

TUNNEL KILN.

APPLICATION FILED SEPT. 3| 1920.

l 1,403,734. Patented Jan.17,1922,

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APPLICATION FILED SEPT. 3y 1920. 1,403,734, Patented Jan. 17, 1922.

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p @Hifi III UNITED STATES PATENT OFFICE.`

GEORGE W. BOOTH, 0F ISLINGTON, ONTARIO, CANADA.

TUNNEL Kimi.

VSpecification of Letters Patent.

Patented Jan. Y17, 1922.

Application led September 3, 1920. Serial No. 4073942.

.kiln to reduce its cost, to secure better control of the preheating, firing and cooling of the goods than before, and to secure the desired results with the use of a minimum amountof fuel.

- Fig. 1;

l attain my'object by means or the constructions hereinafter described and illustrated in the accompanying drawings in which- Fig. 1 is a longitudinal'section elevation, partly broken away,` of part of thekiln;

Fig. 2 a. similar view of the remainder of the kiln;

f Fig. y3 a cross section on the line a-a in Fig. l;

Fig. 4 a cross section on the line ob in F ig.V 5 a cross sectionvon the line c-o in Fig. 2;

Fig. 6 a cross section on the line d-Ziu Fig. 2;

Fig.' 7 a'section on the line e-e in Fig. 1; Fig. 8 a section on the line f-f in Fig. 1; Fig. 9 a horizontal longitudinal section of .part of the kiln; and

Fig. 10 a similar view of the remainder of Y the kiln.

In' the drawings like numerals otv reference indicate corresponding parts inthe different figures.Y

1 is the tunnel ot the kiln. which extends from end to end thereof and comprises three Zones, the preheating Zone, which extends substantially rom'A to B, the tiring zone from B to C and the cooling Zone from C to D.

In the walls of the cooling zone yor the tunnel are formed side air spaces 2 and the top air space 3. The air spaces 2 extend to the beginning of the tiring zone of the kiln, while the air space S'extends over the top of the tiring zone of the kiln asffar as the end-ofthe said firing zone, so that the air passing therethrough takes up heat from the top of the tunnel of vthe cooling and `lapping the firing zone.

ringzones. The transverse lues 4; connect the air spaces 2 with the top air space 3 where the cooling zone adjoins the firing zone, so that all the preheated air in the sides 'and top of the cooling Zone is led through the top air space over the tiring zone. Pret'- erably openings 5 areV provided inthe top of the tunnel in the cooling zone communicating with the air space 3, so that heated air from the cooling goods may pass up into the air space 3.

i Dampers 6 are preferably provided at the outlet end of the kiln through which loutside air may be introduced into the air spaces V2 and 3.

Along the sides of the firing zone of the Vkiln are located one or more furnaces 7 of any .ordinary type, which communicate with the interior of the tunnel through openings 8 located at about the level of the top ofthe trucks 9 on which the goods are transported point adjacent the preheating zone. `At'this point the tunnel will sometimes be provided with a door 10 by means of which the tiring zone may be separated from the preheating zone. This door will usually be arranged in the ordinary'manner to be opened and closed simultaneously with the opening of the door l1 at the inlet end of the tunnel. At this point the hot products of combustion pass'out through the openings 13 into the transverse fiue 14 which leads the products of combustion into the longitudinal side flue 15 extending along one side of the preheating zone of the kiln and preferably over- This overlapping portion is provided with a plurality of damper controlled openings 28 leading from the interior of the firing zone or' the tunnel at diierent distances from the preheating zone. More or lessV ofthe products of combustion may thus be'rem'oved from the tunnel before the transverse flue 111 is reached.

Through a transverse'flue 16 the heated air from the air space 3 is normally led to the longitudinal side flue 17 extending along the preheating zone of the kiln at the opposite side of the kiln to the flue 15. This transverse flue also communicates With the side flue 15 so that preheatedair may be led to both the side flues 15 and 17. Dampers and 17.

18 are provided whereby the communications may be controlled. Normally the pre heated air will flow along the side flue 17, but more or less may he admitted to the ilus 15 as conditions may require. lt will `be noted that the inner walls of the flue l5 und 17 are preferably of metal so that heat is readily conducted through them to preheat tlshi goods passing through. this saone ci? the The preheated air may be admitted, ifi desired, into the interior of the kiln at various points along the preheating zone through damper controlled openings 19. Moist air from the goods passing through the preheating zone is allowed to escape through a series of damper controlled openings 2O into two moist air flues 21 located below the flues 15 These moist air iues communicate at the inlet end of the kiln with the transverse flue 22 which communicates with the stack 23. The fines 15 and 17 communicate with the transverse flue 24:, which also co1n municates with the stack 23, thus the moist air, the preheated air and the products of combustion are all taken offby the stack. At times it is desirable to admit coldair to the interior of the preheating zone of the furnace to `reduce the temperature and I therefore provide the series of damper controlled openings 28 for this purpose.

At times it is advantageous to supply preheated air to the furnaces and suitable fines 25 are provided for this purpose communicating with the preheated air spaces and by damper controlled openings 26 with the furnaces. The furnaces at either side are sep arated from one another and from the `i'lues 15 and17 by transverse walls 27.

I find that a kiln constructed as hereinbe fore described is not only cheaper to build than the form described in my previous patent but also aifords better control of the heat in the tiring zone, and of the preheating of the goods and the drawing away of the moist air therefrom.

What I claim as my invention is 1. A tunnel kiln having an air space formed in its walls extending longitudinally of the preheating, firingand cooling zones4 of the kiln; a furnace communicating with the interior of the firing zone of the tunnel adjacent the cooling zone; a stack adjacent the inlet end of the preheating zone; a iiue communicating with the interior of the firing zone of the tunnel and extending along the preheating zone of the furnace to the stack; and a flue forming a communication between the stack and the air space aforesaid adjacent the inlet end of the tunnel.

2. A tunnel kiln constructed substantially as set forth in claim l provided with a moist air flue communicating with the stack extendin longitudinally of the preheating zone` o the tunnel and a plurality of passages :from the preheating zone to the said flue at different points longitudinally of the j jreheating Zone of the kiln.

3. A tunnel kiln constructed substantially as set Jforth in claim l provided with a damper controlled communication between the air space and the flue carrying the products of combustion from the tiring Zone of the tunnel, said communication being located substantially at the end of the iiring Zone adjacent the preheating zone.

4. A tunnel kiln constructed substantially as set forth in claim 1 provided with a moist air Hue communicating with the stack extending longitudinally of the preheating zone of the tunnel and a plurality of passages rom the preheating zone to the said flue at different points longitudinally of the preheating zone of the kiln, and a series of damper controlled openings between the air space and the interior of the tunnel at different points longitudinally oit the preheating zone of the tunnel.

5.`A tunnel kiln, including preheating, firing and cooling Zones, having separated air spaces extending longitudinally of the walls of its cooling zone, an air space ex tending longitudinally through the top of both the cooling and iii-ing zones; a transverse flue substantially at the junction of the firing and cooling Zones connecting the side air spaces with the top air space; a flue at one side of the preheating zone communicatable with the interior of the tunnel at the adj acent end of the firing zone; a flue at the other side of the preheating zone communicatable with the top air space at the adjacent end ot' the firing zone; and a stack at the inlet end of the tunnel communicating with both flues.

6. A tunnel kiln, including preheating, tiring and cooling zones, having an air space extending longitudinally of the cooling zone and along the top of the firing zone; a iiue at one side of the preheating zone communicatable with the interior of the tunnel at the adjacent end of the tiring zone; a lue at the other side of the preheating zone communicatable with the top air space at the adjacent end of the tiring zone; and a stack at the inlet end of the tunnel communicating with both lues.

7. A tunnel kiln constructed as set forth in claim 6 provided with a moist air flue belenT each of the side tlues, each communicatable with the stack and each communicating with the interior of the tunnel at a number of diferent points longitudinally of the preheating zone of the kiln.

8. A tunnel kiln constructed as set forth in claim 6 provided with a damper controlled communication between the top air space and the flue for the products of combustion.

9. A tunnel kiln constructed as set forth in claim 6 in which the side ilue forming a communication between the iirng zone of ing a damper controlled communication with the tunnel and the stack overlaps the firing the longitudinal air 'space whereby preheated lo zone and communicates therewith by means air may be supplied to the furnaces as deof a plurality of damper controlled openings sired.

at different points longitudinally of the kiln. Signed at Toronto, Canada, this 28th day 10. A tunnel kiln constructed as set forth of August, 1920.

in claim 6 in which the firing zone is provided With a plurality of furnaces each hav- GEORGE W. BOOTH. 

